This invention relates to a cylinder lock with combination of pins, and more particularly, to a lock device which includes a cylinder having a plurality of combination of mechanical pins and magnetic pins.
Most of conventional lock devices utilizing mechanical pins are well known in the art. The cylinder of these lock devices include a cylindrical plug that is rotatably mounted in a outer shell, and provide two groups of pin bores separately in the plug and in the shell which align with each other. Pins are installed slidingly in these pin bores. If a key is not inserted, a pin will bridge the shear plane between the plug and the shell in each bore, as the pin partly extend in the bore of the plug and at the same time it partially extends in the bore of the shell, so as to maintain the lock in the locked condition. Oppositely, if a key is inserted, the raised portions of the key will drive the pins which bridge the shear plane between the plug and the shell into the pin bores of the shell, with the result that the plug can be rotated relatively with the shell.
In the process of producing conventional cylinder lock, the inner diameter of the pin bore is formed several hundred micrometers bigger than the outer diameter of the pin, so that the plug can be rotated a certain angle relatively with the shell, for making the pin move along the pin bore smoothly, even if the key is not inserted; and the pins of the cylinder can directly touch the raised portions of the key inserted from the key aperture. Therefore, such a conventional lock can be unlocked rather easily by the use of a so-called xe2x80x9cmaster-keyxe2x80x9d. One of the typical master key is a metal piece with a little hook at one end of it. When the master key is inserted into the key aperture, turning on the plug forcibly, there will be a relative dislocation between the pins in the plug and the pins in the shell. Then by the hook, pushing each of all pins that bridge the shear plane of lock into the pin bores of the shell one by one. When the pins that have been pushed into pin bores of the shell is pushed back by the action of the coil spring, the pins can not return back into the pin bores of the plug any more because the dislocation between the pins in the plug and the pins in the shell cause the two groups of pin bores disalignment with each other. So that once all of the pins bridging the shear plane of lock are pushed into the pin bores of the shell, this conventional cylinder lock is unlocked.
Chinese Utility Model Publication 2082291 discloses one such cylinder lock including a plurality of magnetic pins that bridge the shear plane between the plug and the shell in each bore, and disposing a plurality of stationary magnets separated in the axial center lines of the magnetic pins. A plurality of magnets are arranged along the length of the key correspondingly the magnetic pins. When the key is inserted into the key aperture, the raised portions of the key and the magnets simultaneously control the mechanical pins and the magnets of the key so as to make the plug and shell rotation with each other in order to unlock the lock. It is an effective method to avoid unlocking the lock with the xe2x80x9cmaster keyxe2x80x9d. Thus, a highly secure lock is provided. But the magnetic pins of this lock are usually located far away from the key aperture due to the attraction of the stationary magnets. For making the key compact for portability, it is usually impossible to make the magnets of the key too big, thus the magnetic attraction of them is quite limited, which frequently results in the unlocking ineffective. On the other hand, by the attraction of the stationary magnets, the magnetic pins bridge the shear plane between the plug and the shell. When suffering an extra intensity vibration, there is much probability that the magnetic pins fall, thus causing the lock to be unlocked. The structure of this lock device is distinct from the structure of conventional cylinder lock; however, it is rather expensive to manufacture.
Accordingly, it is an object of the present invention to provide an improved cylinder lock device that is simple in construction, reliable in unlocking, inexpensive in manufacture, so as to overcome the drawbacks in the art as mentioned above. A further object of the present invention is to provide an improved cylinder lock device that has an advantage of resistance to being disturbed from circumstance.
For realizing the above objects, the present invention provides a lock device comprising a cylinder having at least a group of mechanical pins and a group of magnetic pins; wherein, the group of magnetic pins includes a slidable magnetic pin in the pin bore of the plug and a slidable metal pin in the pin bore of the shell and a coil spring, when the key is not inserted in plug, the metal pin partially extends into the pin bore of plug and bridges the shear plane between the plug and the shell by the action of said coil spring that locates in the pin bore of the shell.
The present invention also provides a key that can be used with the above lock device. When said key is inserted into the plug, a plurality of recesses of key match with the mechanical pins which are disposed in the pin bores of the plug; and a plurality of magnetic balls in the key match with the magnetic pins which are disposed in the pin bores of the plug; and the polarities of the magnetic balls in the key and the opposite magnetic pins on their neighborhood surfaces are identical.
Said bore of plug is a cylindrical blind bore with opening toward the shell. When said key is not inserted, said magnetic pins maintain at the closed ends of the blind bores; and the metal pins are pushed to the magnetic pins and the metal pin normally extends into the pin bore of plug and bridges the shear plane between the plug and the shell by the action of a coil spring.
Within the groups of magnetic pins according to the present invention, the outer diameter of the magnetic pin is formed bigger than the inner diameter of the pin bore of the shell so as to ensure the magnetic pin can not enter the pin bore of the shell.
In order to ensure unique mate between the key and the lock, the polarity of the magnetic pins, which face to the key apertures, is either N or S pole in the each magnetic pins group, and different locks have different combination of polarity orientations of magnetic pin groups.
Within the plug of the cylinder lock according to the present invention, several groups of magnetic pins are disposed along one lengthwise side of the key aperture, and several groups of mechanical pins are disposed along another lengthwise side of the key aperture. It is preferable that said magnetic and mechanical pin groups longitudinally line in a row.
The cylinder lock device with above structure can avoid unlocking by the xe2x80x9cmaster keyxe2x80x9d, because the magnetic pin bores do not communicate with the key aperture. Normally, the magnetic pins locate in a position that is near the key aperture. Therefore, when the key is inserted, the magnetic force is greatest, which produced by the polarity of poles between the magnetic ball in the key and the magnetic pin in the plug, so as to ensure unlocking reliable. Because the compressing of the spring is hardly affected by the outside, the lock device is seldom unlocked due to the outside vibration and the likes. The structure of the cylinder lock device in the present invention is basically the same as that of the conventional cylinder lock. After a little modification based on the product line and the technique of the art, the lock according to the invention can be manufactured immediately. As a result, the cost of manufacture decreases greatly.
The present invention will become apparent from the detailed description taken in conjunction with the preferred embodiments herein below and the accompanying drawings, and wherein: